I'm finding that (i) transfering gps track files to flight visualization software doesnt appear to be a straight forward proposition, and (ii) available instructions for this and many other processes leaves a whole lot to be desired! Now that thats off my chest ..

I use SeeYou and download the .igc file directly from my Garmin 76CSx without any problems. I would consider it very straight forward once set up, but agree the documentation leaves much to be desired.

If SeeYou can not extract a .igc file directly from Garmin, try one of the free conversion applications available such as GPS Babel.

Before owning SeeYou, I used GPS Babel to convert the .gpx Garmin flies to .igc format used by SeeYou

Another problem may exist, that of the Garmin not set to talk to the computer. Hit your menu button and look for the system icon. Scroll down to system and hit enter. A new menu opens. Scroll to interface and hit enter. There is a drop down menu box high lighted, it should say Garmin. This lets your Garmin communicate with your computer. If the drop down box says something else, such as NEMA In/NEMA Out (this option allows your Garmin to comminicate with a GPS orianted vario), hit enter and scroll down and highlight Garmin and hit enter again. If you do have a GPS orianted vario you will have to go back into the menu options and reset it back to NEMA after you download your track logs or upload map detail